Preparation of aromatic polymers using a specified quantity of Lewis acid

ABSTRACT

A process for producing an aromatic polyketone which comprises polymerizing an appropriate monomer or monomers by a Friedel-Crafts polymerization reaction using a Lewis acid catalyst. A controlling agent such as a Lewis base may be added to the reaction medium and/or the reaction is conducted under specified conditions to control the reaction. The reaction medium comprises, for example, aluminum trichloride as the Lewis acid, an organic Lewis base such as N,N-dimethylformamide or an inorganic Lewis base such as sodium or lithium chloride, and a diluent such as methylene chloride or dichloroethane. The amount of Lewis acid, the amount of Lewis base, the temperature of the reaction and the monomer to diluent molar ratio are varied depending on the monomer system to obtain melt-processable, high molecular weight, substantially linear polymers, for example poly(carbonyl-p-phenylene-oxy-p-phenylene), poly(carbonyl-p-phenylene-oxy-p-phenylene-oxy-p-phenylene), and the like. Copolymers containing up to 30% by weight of an aromatic sulfonyl halide comonomer can also advantageously be produced by this process.

This application is a continuation of application Ser. No. 07/186,750,filed Apr. 25, 1988 now abandoned,; which is a continuation ofapplication Ser. No. 07/084,668, filed Aug. 11, 1987, now abandoned;which is a divisional of application Ser. No. 06/922,837, filed Oct. 23,1986, now U.S. Pat. No. 4,709,007; which is a continuation ofapplication Ser. No. 06/594,503, filed Mar. 29, 1984 now abandoned;which is a continuation-in-part of application Ser. No. 06/481,081,filed Mar. 31, 1983, now abandoned; the disclosures of which areincorporated herein by reference.

BACKGROUND OF THE INVENTION

This invention relates to a method of preparing poly(arylene ketones)and in particular to an electrophilic polymerization process forpreparing such polymers.

Poly(arylene ketones), in particular, all paralinked poly(aryl etherketones), possess many desirable properties, for example, hightemperature stability, mechanical strength, and resistance towardscommon solvents. The preparation of poly(arylene ether ketones) by twodifferent approaches has been described in the literature. The firstapproach is an electrophilic synthesis in which an aryl ketone linkageis formed. The second is a nucleophilic synthesis in which an aryl etherlinkage is formed. This invention is directed to an improvedelectrophilic synthesis for preparing poly(arylene ketones), inparticular all para-linked poly(aryl ether ketones).

In such an electrophilic synthesis, the polymerization step involves theformation of an aryl ketone group from a carboxylic acid or acidderivative group and an aromatic compound containing an aromatic carbonbearing an activated hydrogen atom, i.e. a hydrogen atom displaceableunder the electrophilic reaction conditions. The monomer system employedin the polymerization can be, for example, (a) a single aromaticcompound containing both a carboxylic acid or acid derivative group aswell as an activated hydrogen atom on an aromatic carbon for example,p-phenoxybenzoyl chloride; or (b) a two-component system of adicarboxylic acid or acid derivative and an aromatic compound containingtwo activated hydrogen atoms, for example, 1,4-diphenoxybenzene andterephthaloyl chloride.

Electrophilic polymerization of this type is often referred to asFriedel-Crafts polymerization. Typically, such polymerizations arecarried out in a reaction medium comprising the reactant(s), a catalyst,such as anhydrous aluminum trichloride, and solvent such as methylenechloride, carbon disulfide, nitromethane, nitrobenzene, ororthodichlorobenzene. Because the carbonyl groups of the reactant(s) andproducts complex with aluminum trichloride and thereby deactivate it,the aluminum trichloride catalyst is generally employed in an amountgreater than one equivalent for each equivalent of carbonyl groups inthe reaction medium. Other inorganic halides such as ferric chloride maybe employed as the catalyst.

Such Friedel-Crafts polymerizations generally have produced and/or anintractable reaction product difficult to remove from the reactionvessel and purify. Further, such processes have tended to producepolymer of undesirably low molecular weight and/or of poor thermalstability. The all para-linked poly(arylene ether ketones) have beenparticularly difficult to prepare under such Friedel-Crafts conditions.One factor that appears to contribute to the unsatisfactory resultsreported in the literature is that the all-para polymers are more highlycrystalline than the ortho, meta or mixed isomeric members of thispolymer family and are generally more insoluble in the reaction mediatypically used in such Friedel-Crafts reactions. This tends to result inthe premature precipitation of the polymer in low molecular weight form.Another factor that may lead to these poor results is deactivation ofthe terminal aryloxy groups by complexation with aluminum chloride oralkylation of the terminal group which prevents further growth of thepolymer chain. Also, side reactions, particularly at the ortho positionof activated aromatic rings can result in a polymer that is branchedand/or is more likely to cross-link at elevated temperatures such asthose required for melt processing the polymer. It is generallyrecognized that in Friedel-Crafts reactions, ortho substitution of thepolymer is more likely to occur if the reaction is conducted at elevatedtemperatures for a relatively long reaction time. U.S. Pat. Nos.3,065,205 to Bonner, U.S. Pat. No. 3,767,620 to Angelo et al, 3,516,966to Berr, 3,791,890 to Gander et al, 4,008,203 to Jones and U.K. Pat.Nos. 971,227 and 1,086,021 both to Imperial Chemical Industries,Limited, disclose the preparation of poly(arylene ketones) byFriedel-Crafts polymerization and generally acknowledge some of thedifficulties in producing tractable, melt-stable polymers. For example,Gander et al provide a method of producing the polymers in granular formby special treatment of the reaction mixture before gellation can occurand Angelo et al provide a method of treating the polymer to reduceundesired end goups which result from side reactions duringpolymerization and which cause thermal instability of the polymer.

To overcome the disadvantages encountered in producing poly(aryleneketones) by the above described Friedel-Crafts polymerization, it hasbeen proposed to use boron trifluoride catalyst in anhydrous hydrogenfluoride. See for example, U.S. Pat. Nos. 3,441,538 to Marks, 3,442,857to Thornton, 3,953,400 to Dahl, and 3,956,240 to Dahl et al. Thisgeneral process has been used commercially to produce polymer of thedesired high molecular weight and thermal stability. However, the use ofboron trifluoride and hydrogen fluoride requires special techniques andequipment making this process difficult to practice on a commercialscale.

We have now discovered an improved process for the production ofpoly(arylene ketones) by an electrophilic synthesis which results inhigh molecular weight, thermally stable polymers using reaction mediathat are readily handled on a commercial scale. The process of theinvention provides a high reaction rate which enables the reaction to becarried out at relatively low temperatures over a relatively shortperiod of time. Further, the polymer is maintained in the reactionmedium, for example in solution or in a reactive gel state, until highmolecular weight polymer is obtained. Further, the polymer produced isessentially linear with little, if any, ortho substitution of thearomatic rings in the polymer backbone. Since the process of thisinvention maintains the polymer in solution or in a more tractablestate, recovery and purification of the polymer is greatly facilitated.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a graph illustrating the effect of the amount of Lewis acidpresent during the polymerization on the inherent viscosity ofpoly(carbonyl-p-phenylene-oxy-p-phenylene).

SUMMARY OF THE INVENTION

In accordance with the process of this invention, the Friedel-Craftspolymerization of appropriate monomer systems, as defined more fullyhereinafter, is controlled to suppress side reactions including orthosubstitution, alkylation and chain branching an/or to solubilize orswell the polymer, by conducting the reaction under select reactionconditions and proportions of reactants not taught or suggested by theprior art or by the addition of a controlling agent, such as a Lewisbase, to the reaction medium or both.

One aspect of this invention comprises a method of producing apoly(arylene ether ketone) which comprises polymerizing (I) phosgene oran aromatic diacid dihalide together with a polynuclear aromaticcomonomer containing two active hydrogen atoms or (II) a polynucleararomatic comonomer containing both an acid halide group and an activehydrogen atom, in the presence of a Lewis acid, optionally a controllingagent and optionally a non-protic diluent, the various components beingpresent in proportions and the polymerization being conducted underreaction conditions such that a thermally stable, linear poly(aryleneether ketone) substantially free of pendant groups resulting from orthosubstitution of para-linked aromatic rings in the polymer backbone isobtained.

Another aspect of this invention comprises a method of producingpoly(arylene ether ketones) which comprises polymerizing a monomersystem comprising:

(I)

(i) phosgene or an aromatic diacid dihalide together with

(ii) a polynuclear aromatic comonomer comprising:

(a) H--Ar--O--AR--H

(b) H--(Ar--O)_(n) --Ar--H, wherein n is 2 or 3

(c) H--Ar--O--A r--(CO--Ar--O--Ar)_(m) -H, wherein m is 1, 2 or 3 or

(d) H--(Ar--O)_(n) --Ar--CO--Ar--(O--Ar)_(m) -H, wherein m is 1, 2 or 3,and n is 2 or 3 or

(II) an acid halide of the formula:

    H--Ar--O--[(Ar--CO).sub.p --(AR--O).sub.q --(Ar--CO).sub.r ].sub.k--Ar--CO--Z

wherein Z is halogen, k is 0, 1 or 2, p is 1 or 2, q is 0,1 or 2 and ris 0, 1 or 2; or

(III) an acid halide of the formula:

    H--(Ar--O).sub.n --Ar--Y

wherein n is 2 or 3 and Y is CO--Z or CO--Ar--CO--Z, where Z is halogen;

wherein each Ar is independently selected from substituted orunsubstituted phenylene, and substituted and unsubstituted polynucleararomatic moieties free of ketone carbonyl or ether oxygen groups;

in a reaction medium comprising

(A) a Lewis acid in an amount of one equivalent per equivalent ofcarbonyl groups present plus one equivalent per equivalent of Lewisbase, plus an amount effective to act as a catalyst for thepolymerization;

(B) a Lewis base in an amount from 0 to about 4 equivalents perequivalent of acid halide groups present in the monomer system; and

(C) a non-protic diluent in an amount from 0 to about 95% by weight,based on the weight of the total reaction mixture;

with the provisos that in the substantial absence of Lewis base and:

(i) the monomer system includes a diacid dihalide and a comonomer asdefined in I(ii)(a), I(ii)(b) or I(ii)(d):

(aa) the Lewis acid is present in excess of the minimum specified in(A)above by an amount of up to 0.8 equivalents per equivalent ofundeactivated aryloxy groups in the monomers, and, if the acid halidegroup are situated on separate non-fused aromatic rings, by anadditional amount of up to 0.5 equivalents per equivalent of acid halidgroups; and

(bb) the concentration of monomers in the reaction mixture is at least7% by weight, based on the total weight of the reaction mixture; withthe further proviso that when the monomer system includes a comonomer asdefined in I(ii)(a) and the diacid dihalide is benzene dicarbonyldichloride or diphenyl ether dicarbonyl dichloride, the polymer producedis at least partially crystalline;

(ii) the monomer system is III, the Lewis acid is present in excess ofthe minimum specified in (A) above by an amount of up to 0.8 equivalentper equivalent of undeactivated aryloxy groups in the monomers; or

(iii) the monomer system is I(c) or II, the Lewis acid is present in anamount in excess of the minimum specified in (A) above by at least0.6+[0.25×tanh (50(0.1-D)] equivalents per equivalent of acid halidegroups where D is the molar ratio of monomer to diluent.

DETAILED DESCRIPTION OF THE INVENTION

In the electrophilic polymerization of this invention a poly(aryleneether ketone) is produced from an appropriate monomer system. Thepolymers produced by the process of the invention have repeat units ofthe general formula ##STR1## wherein each Ar is independently selectedfrom substituted and unsubstituted phenylene and substituted andunsubstituted polynuclear aromatic moieties. The term polynucleararomatic moieties is used to mean aromatic moieties containing at leasttwo aromatic rings. The rings can be fused, joined by a direct bond orby a linking group. In certain of the monomers, e.g. the polynucleararomatic comonomers, the acid halide monomers and certain diaciddihalides, at least two of the aromatic rings are linked by an etheroxygen linkage. Other linking groups which can join aromatic rings inthe aromatic moieties include for example, carbonyl, sulfone, sulfide,amide, imide, azo, alkylene, perfluoroalkylene and the like.

The phenylene and polynuclear aromatic moieties can containsubstitutents on the aromatic rings. These substituents should notinhibit or otherwise interfere with the polymerization reaction to anysignificant extent. Such substituents include, for example, phenyl,halogen, nitro, cyano, alkyl, 2-aralenyl, alkynyl and the like.

These polymers are prepared in accordance with this invention bypolymerizing an appropriate monomer system. Such monomer systemscomprise:

(I)

(i) phosgene or an aromatic diacid dihalide together with

(ii) a polynuclear aromatic comonomer selected from

(a) H--Ar--O--Ar--H

(b) H--(Ar--O) _(n) --Ar--H, wherein n is 2 or 3

(c) H--Ar--O--Ar--(CO--Ar--O--Ar)_(m) -H, wherein m is 1, 2 or 3 or

(d) H--(Ar--O)_(n) --Ar--CO--Ar--(O--Ar)_(m) -H, wherein m is 1, 2 or 3,or

(II) an acid halide of the formula:

    H--Ar--O--[(Ar--CO).sub.p --(Ar--O).sub.q --(Ar--CO).sub.r ].sub.k --Ar--CO--Z

wherein Z is halogen, k is 0, 1 or 2, p is 1 or 2, q is 0, 1 or 2 and ris 0, 1 or 2; or

(III) an acid halide of the formula:

    H--(Ar--O).sub.n --Ar--Y

wherein n is 2 or 3 and Y is CO--Z or CO--Ar--CO--Z, wherein Z ishalogen;

wherein each Ar is independently selected from substituted orunsubstituted phenylene, and substituted and unsubstituted polynucleararomatic moieties free of --CO--and --O-- groups.

Aromatic diacid dihalide employed is preferably a dichloride ordibromide. Illustrative diacid dihalides which can be used include, forexample ##STR2## wherein a is 0-4.

Illustrated polynuclear aromatic comonomers which can be used with suchdiacid halides are:

(a) H--Ar--O--Ar--H, which includes, for example: ##STR3## (b)H--(Ar--O)_(n) --Ar--H, which include, for example: ##STR4## (c)H--Ar--O--Ar--(CO--Ar--O--Ar)_(m) --H, which includes, for example:##STR5## And (d) H--(Ar--O)_(n) --Ar--CO--Ar--(O--Ar)_(m) --H whichincludes, for example: ##STR6##

Monomer systems II and III comprise an acid halide. In monomer systemII, the acid halide is of the formula

    H--Ar--O--[(Ar--O).sub.p --(Ar--O).sub.q (Ar--CO).sub.r ].sub.k --Ar--CO--Y

Such monomers include for example, where k=0 ##STR7##

and where k=1 ##STR8##

In monomer system III, the acid halide is of the formula

    H--(Ar--O).sub.n --Ar--Y

Examples of such acid halides include ##STR9##

It is to be understood that combinations of monomers which fall withinthe same proviso clause, as set forth above, can be employed. Forexample one or more diacid dihalides can be used with one or morepolynuclear aromatic comonomers as long as the correct stoichiometry ismaintained. Further, one or more acid halides can be included. Inaddition monomers which do not contain an ether linkage can be employedas long as one or more comonomer used contains at least one ether oxygenlinkage. Such comonomers include for example: ##STR10## which can beused as the sole comonomer with an ether containing diacid dihalide orwith phosgene or any diacid dihalide when used in addition to apolynuclear aromatic comonomer as defined in I(ii)(a), I(ii)(b),I(ii)(c) or I(ii)(d). Similarly ##STR11## can be used as a comonomertogether with an ether-containing polynuclear aromatic acid halide or asan additional comonomer together with a monomer system as defined in I.

The monomer system is polymerized in the presence of a reaction mediumcomprising:

(A) a Lewis acid in an amount of one equivalent per equivalent ofcarbonyl groups present, plus one equivalent per equivalent of Lewisbase, plus an amount effective to act as a catalyst for thepolymerization;

(B) a Lewis base in an amount from 0 to about 4 equivalents perequivalent of acid halide groups present in the monomer system; and

(C) a diluent in an amount from 0 to 95% by weight, based on the weightof the total reaction mixture.

The term "Lewis acid" is used herein to refer to a substance which canaccept an unshared electron pair from another molecule. Lewis acidswhich can be used in the practice of this invention include, forexample, aluminum trichloride, aluminum tribromide, antimonypentachloride, antimony pentafluoride, indium trichloride, galliumtrichloride, boron trichloride, boron trifluoride, zinc chloride, ferricchloride, stannic chloride, titanium tetrachloride, and molybdenumpentachloride. The use of substantially anhydrous aluminum trichlorideas the Lewis acid is preferred.

The amount of Lewis acid used in the practice of this invention variesdepending on the particular monomers and reaction medium selected. Inall instances at least one equivalent of Lewis acid per equivalent ofcarbonyl groups present in the monomer system is used plus an amounteffective to act as a catalyst for the polymerization (also referred toherein as a catalytic amount). Generally a catalytic amount added isfrom about 0.05 to about 0.3 equivalents of Lewis acid per equivalent ofacid halide in the reaction mixture. Additional amounts of Lewis acidare also required depending on the nature of the monomers and thereaction conditions in a manner as set forth below. Further, if acomonomer containing other bsic species, such as sulfone groups, isused, additional Lewis acid may be required. As indicated above, theFriedel-Crafts polymerization reaction is controlled by the addition ofa controlling agent or by varying the reaction conditions, includingvarying the amount of Lewis acid to achieve the desriedmelt-processable, high molecular weight, substantially linearpoly(arylene ether ketones).

In a preferred embodiment of the invention, the polymerization reactionis controlled by the addition of a controlling agent which, inter alia,suppresses undesirable side reactions, particularly ortho substitutionof activated aryloxy groups. Suppression of side reactions results in apolymer that is thermally stable, that is it does not degrade orcross-link when subjected to elevated temperatures, e.g. temperaturesabove the melting point of the polymer, for a period of time. For apolymer of this type to be suitable for melt processing, it must be ableto withstand the processing temperatures for the required processingtime. Typically these conditions require that the polymer can withstandtemperatures up to about 30° C. above the melting or softening point ofthe polymer for periods of at least 30 minutes, preferably at least 60minutes and most preferably at least 90 minutes, without undesired gelformation or change in inherent viscosity.

Preferred controlling agents for the polymerization are Lewis bases. Theterm "Lewis base" is used herein to refer to a substance capable ofdonating an unshared electron pair to a Lewis acid. Thus, the Lewis baseforms a complex with the Lewis acid used in the reaction medium. It hasbeen found that Lewis bases which for a 1:1 complex having a heat ofassociation greater than that of diphenyl ether with the Lewis acid arepreferred. For example, where aluminum trichloride is the Lewis acid theLewis base used should form a 1:1 complex having a heat of associationof at least about 15 kcal/mole, preferably at least about 20 kcal/moleand most preferably at least about 30 kcal/mole. While the heats ofassociation are for a 1:1 Lewis acid/Lewis base complex consiting solelyof these two components, the actual complex formed need not be a 1:1complex. The Lewis base used should not be an acylating, alkylating orarylating agent nor should it be acylatable under the reactionconditions. Mixtures of two or more Lewis bases can be used if desired.The Lewis base used as a controlling agent in the practice of thisinvention is an additional component added to the reaction medium. Thisdoes not include basic species formed in situ during the polymerization.

Typical Lewis bases which can be employed include, for example, amides,amines, esters, ethers, ketones, nitriles, nitro compounds, phosphines,phosphine oxides, phosphoramides, sulfides, sulfones, sulfonamides,sulfoxides, and halide salts.

Examples of specific organic Lewis bases that can be used in thepractice of this invention are acetone, benzophenone, cyclohexanone,methyl acetate, ethylene carbonate, N-methylformamide, acetamide,N,N-dimethylacetamide, N-methylpyrrolidone, urea, tetramethylurea,N-acetylmorpholine, dimethyl sulfoxide, N,N-dimethylformamide, diphenylsulfone, N,N-dimethylmethanesulfonamide, phosphoryl chloride,phenylphosphonyl chloride, pyridine-N-oxide, triphenylphosphine oxide,trioctylphosphine oxide, nitropropane, nitrobenzene, benzonitrile,n-butyronitrile, methyl ether, tetrahydrofuran, dimethyl sulfide,trimethylamine, N, N, N', N'-tetramethylethylenediamine,N,N-dimethyldodecylamine, imidazole, pyridine, quinoline, isoquinoline,benzimidazole, 2,2'-bipyridine, o-phenanthroline,4-dimethylaminopyridine, and the like. In addition to covalent organiccompounds, suitable Lewis bases include inorganic salts which can formcomplexes with Lewis acids, for example, chlorides, such astrimethylammonium chloride, tetramethylammonium chloride, sodiumchloride or lithium chloride, perchlorates, trifluoromethanesulfonatesand the like.

Preferred Lewis bases for the reaction medium of this invention areN-methylformamide, N,N-dimethylformamide, N,N-dimethylacetamide,1-methyl-2-pyrrolidone, tetramethylene sulfone (also known assulfolane), n-butyronitrile, dimethyl sulfide, imidazole, actone,benzophenone, trimethylamine, trimethylamine hydrochloride,tetramethylammonium chloride, pridine-N-oxide, 1-ethylpyridiniumchloride, lithium chloride, lithium bromide, sodium chloride, sodiumbromide, potassium chloride, potassium bromide and mixtures thereof.

The amount of Lewis base present should be from 0 to about 4 equivalentsper equivalent of acid halide groups present in the monomer system.Amounts greater than 4 equivalents could be employed, if desired.However, no additional controlling effect is usually achieved by addinglarger amounts. Thus, it is preferred to use no more than about 4equivalents and generally about 2 equivalents. When a Lewis base isadded to control the reaction at least about 0.01, preferably about 0.05and most preferably about 0.5 equivalents of Lewis base per equivalentof acid halide groups present should be used. The particular amount ofLewis base added depends to a certain extent on the nature of themonomers present. When a Lewis base is used to control the reaction thetemperature at which the reaction is conducted can be from about -50° C.to about +150° C. It is preferred to start the reaction at lowertemperatures, for example at about -50° to about -10° C. particularly ifthe monomer system contains particularly reactive monomers. Afterpolymerization has commenced the temperature can be raised if desired,for example, to increase the rate of reaction. It is generally preferredto carry out the reaction at temperatures in the range of between about-30° C. and +25° C. (room temperature).

While it is not understood exactly how the Lewis base acts to controlthe reaction, it is believed that one or more of the following factorsmay be invloved. The Lewis acid/Lewis base complex appears to act as asolvent for the polymer-Lewis acid complex formed during the reaction,thereby maintaining the polymer in solution or a reactive gel state.Further, the reaction mixture is more tractable, making work up of thepolymer easier and ensuring effective removal of catalyst residuesduring purification. The solubilization property of the Lewis acid/Lewisbase complex is particularly significant in the preparation of allpara-linked poly(arylene ether ketones). As mentioned above thesepolymers are more highly crystalline than other members of this polymerfamily and their complexes with the Lewis acid tend to precipitate fromthe reaction medium in low molecular weight form and/or in aparticularly intractable mass extremely difficult to recover and purify.When such polymers are made in accordance with this embodiment of theinvention, it is advantageous to select a Lewis acid and Lewis basecombination which form a complex which, in addition to the abovespecified characteristics, also dissolve the desired polymer. This caneasily be determined by preparing a complex, optionally adding adiluent, and then adding the polymer to see if it dissolves.

If a diluent such as methylene chloride or dichloroethane is used, thatthe Lewis acid/Lewis base complex reduces the tendency of these diluentsto act as an alkylating agent by competing with the diluent foravailable Lewis acid and thereby suppresses alkylation of the polymer.Alkylation of the polymer in the para position caps the reaction whilealkylation in the ortho position introduces undesired reactive cites inthe polymer chain which can lead to branching or cross linking.

It is believed that the aromatic rings which are particularlysusceptible to ortho substitution are active aryloxy groups. Such groupsare referred to herein as undeactivated aryloxy groups. By"undeactivated aryloxy group" is meant an aryloxy group which is in amolecule in which there are no deactivating groups or is located atleast two aromatic moieties (i.e. Ar as defined above) away from adeactivating group such as a carbonyl. Conversely a "deactivated aryloxygroup" is an aryloxy group separated from a deactivating group, usuallycarbonyl, by an aromatic group containing one aromatic ring, fusedaromatic rings or aromatic rings liked by direct bonds.

A diluent can also be employed, if desired. Advantageously, the diluentshould dissolve the Lewis acid/Lewis base complex and the resultingpolymer/Lewis acid complex but this is not an essential requirement ofthe diluent. It should also be relatively inert toward Friedel-Craftsreactions. The diluent is preferably somewhat polar as measured by itsdielectric constant and solubility parameter. Preferably the dielectricconstant of the diluent is at least about 2.5 at 24° C., and preferablyin the range of from about 4.0 to about 25° at 24° C. The Hildebrandsolubility parameter of the diluent is preferably at least about 7.2[cal/cm³ ]^(1/2) and is preferably in the range of from about 9.2 toabout 15 [cal/cm³ ]^(1/2). Preferred diluents include, for example,methylene chloride, carbon disulfide, o-dichlorobenzene,1,2,4-trichlorobenzene, o-difluorobenzene, 1,2-dichloroethane,1,2,3,4-tetrachloroethane and tetrachloroethylene.

The diluent is used in an amount from 0 to about 95% by weight, based onthe weight of the total reaction mixture. As is known in polymerizationsof this type, the reactions can be run neat, that is without thepresence of a diluent. This is true for the process of this inventionwhether or not a Lewis base is used. As discussed in more detail below,it has been found that the monomer to diluent ratio can contribute tocontrol of the polymerization reaction to yield the desired product.

Use of an alkylating or acylating diluent can lead to undesired sidereactions as mentioned above. When such solvents are employed control ofthe polymerization by techniques taught in this specification suppressessuch alkylation or arylation. The result is a thermally stable, meltprocessable, essentially linear polymer.

The polymerization reaction can also be moderated by use of theappropriate reaction conditions without the addition of a Lewis base.The reaction conditions required depend on the reactivity of themonomers used. Two general classes of monomers need to beconsidered--those containing undeactivated aryloxy groups as definedabove and those which do not. If any monomer in the monomer systemcontains an undeactivated aryloxy group, the amount of Lewis acid usedgenerally must not exceed a certain amount.

Monomer systems which can be used in the practice of this invention havebeen defined above with consideration of the reactivity of the aryloxygroups present. The conditions under which the polymerization will bemoderated to produce the desired product can then be set forth withfurther requirements indicated where the relative activity of the acidhalide groups make this necessary.

Briefly, the monomer systems are:

(I)

(i) phosgene or an aromatic diacid dihalide together with

(ii) a polynuclear aromatic comonomer comprising:

(a) H--Ar--O--Ar--H

(b) H--(Ar--O)_(n) --Ar--H, wherein n is 2 or 3

(c) H--Ar--O--Ar--(CO--Ar--O--Ar)_(m) -H, wherein m is 1, 2 or 3 or

(d) H--(Ar--O)_(n) --Ar--CO--Ar--(O--Ar)_(m) -H, wherein m is 1, 2 or 3,and n is 2 or 3 or

(II) an acid halide of the formula:

    H--Ar--O--[(Ar--CO).sub.p --(Ar--O).sub.q --(Ar--CO).sub.r ].sub.k --Ar--CO--Z

wherein Z is halogen, k is 0, 1 or p is 1 or 2, q is 01 or 2 and r is 0,1 or 2; or

(III) an acid halide of the fomula:

    H--(Ar--O).sub.n --Ar--Y

wherein n is 2 or 3 and Y CO--Z or CO--Ar--CO--Z, wherein Z is halogen;

wherein each Ar is independently selected from substituted orunsubstituted phenylene, and substituted and unsubstituted polynucleararomatic moieties free of ketone carbonyl and ether oxygen groups.

Monomer systems that contain undeactivated aryloxy groups are I whereinthe comonomer is as defined in I(ii)(a), I(ii)(b), I(ii)(d) and III. Ingeneral, when monomers of this type are used the amount of Lewis acidpresent in addition to the above noted one equivalent per equivalent ofcarbonyl groups present plus an amount effective to act as a catalystfor the polymerization, should be less than 0.8 equivalents perequivalent of undeactivated aryloxy groups. Preferably even less thanthat should be used, for example less than about 0.6 equivalents andmost preferably less than about 0.4 equivalents per equivalent ofundeactivated aryloxy groups present. However, because of the reactivityof certain polynuclear diacid dihalides such as diphenyl etherdicarbonyl dichloride, it has been found desirable to employ a differentamount of Lewis acid when such diacid dihalides are used in the monomersystem. When such polynuclear diacid dihalides are used in monomersystem I with a comonomer defined in I(ii)(a), I(ii)(b) and I(II)(d) itis often desirable to add further Lewis acid up to 0.5 equivalents perequivalent of acid halide groups. Preferably the further amount added isbetween about 0.03 and 0.5 equivalents per equivalent of acid halidegroups. We have found that meta-benzene dicarbonyl dichloride issufficiently reactive and the product sufficiently soluble in thereaction medium that it is not necessary to limit the maximum excess ofLewis acid to obtain high molecular weight polymer. However, to preparepolymers which are at least partly crystalline from monomer systemsincluding substantial amounts of the less reactive para benzenedicarbonyl dichlorides, it is very beneficial to use an amount of Lewisacid in excess of that defined in (A) above by an amount of up to 0.8equivalents per equivalent of undeactivated aryloxy groups in themonomers.

It has also been found to be necessary when the monomer system used is Iwith the comonomer being that defined in I(ii)(a), I(ii)(b) or I(ii)(d)that the concentration of monomers in the reaction mixture be at leastabout 7%, preferably at least about 10%, and most preferably at leastabout 15%, by weight based on the total weight of the reaction mixture.

When the monomer system employed is III, it is also desirable to conductthe reaction at similar monomer concentrations.

The second general class of monomers are monomer systems which containno undeactivated aryloxy groups. Monomers of this type are set forth inmonomer system I wherein the comonomer is as defined in I(ii)(c) and II.With this class of polymers it is preferred to use a large excess ofLewis acid, the excess depending on the particular monomer to diluentmolar ratio (D). Generally, it is preferred to have a relatively highmonomer to diluent ratio and a relatively large excess of Lewis acid.The amount of excess Lewis acid (in addition to the above notedequivalent per equivalent of carbonyl groups plus a catalytic amount) isat least about 0.6+(0.25×tanh [50(0.1)]) equivalents per equivalent ofacid halide groups. The amount of excess Lewis acid is preferbly at lest0.8+(0.25×tanh [50(0.1-D)]) and most preferably is at least1.0+(0.25×tanh [50(0.1-D)]) equivalents per equivalent of acid halidegroups. When the monomer to diluent ratio is greater than about 0.15,the amount of Lewis acid in excess of the standard amount is at leastabout 0.3 equivalents per equivalent of acid halide groups.

In general, it is preferred to add Lewis acid in a substantial excess ofthe minimum amounts specified. Generally, at least 0.5 equivalent andpreferably at least about 1.0 equivalents of additional Lewis acid, perequivalent of acid halide groups are used.

The reaction conditions found to be necessary to preparemelt-processable, high molecular weight, substantially linearpoly(arylene ether ketones) are not taught or suggested by the prior artand in fact are contrary to the generally held beliefs of Friedel-Craftschemistry. Conventionally, a moderate excess of Lewis acid usually about0.4 equivalents per equivalent of carbonyl groups in the monomer systemis used in Friedel-Crafts reactions. Applicant has found that when allaryloxy groups present the monomer system are deactivatied by arloxygroups as defined above, a large excess of Lewis acid must be used. thisis illustrated in FIG. 1, where the relationship between the amount ofLewis acid used and the molecular weight of the polymer as measured byinherent viscosity as described below. Prior ar Friedel-Craftspolymerization reactions of this type were conducted using proportionsof Lewis acid on the steep part of the curve, well below that needed forthe production of polymer whose molecular weight does not depend on theLewis acid/monomer ratio or used monomer to diluent molar ratios belowthat required. Where there are undeactivated aryloxy groups present inthe monomer system, it has been found to be necessary to add a smallerexcess of Lewis acid than taught in the prior art but to maintain arelatively high monomer concentration in the reaction mixture. Asmentioned above, this results in suppression of side reactions,particularly in the ortho position of para-linked aromatic rings in thepolymer chain. Traditional Friedel-Crafts chemistry suggests the use ofa moderate excess of Lewis acid and a more dilute reaction mixture toachieve these results. Applicants have found the opposite to benecessary in the preparation of poly(arlene ether ketones).

As mentioned above, one of the important features of this invention isthat poly(arlene ketones) of high molecular weight can be obtained. By"high molecular weight" is meant polymer having an inherent viscositygreater than 0.6. Preferably the polymer prepared by the process of thisinvention has an inherent viscosity in the range of about 0.6 to about2.0. Polymers having an inherent viscosity below about 0.6 are generallynot useful because they have poor mechanical properties, such as tensilestrength and elongation. They also tend to be brittle while polymershaving an inherent viscosity above about 2.0 are very difficult to meltprocess. Throughout this application, inherent viscosity refers to themean inherent viscosity determined according to the method of Sorensonet al, "Preparative Methods of Polymer Chemistry" Interscience (1968),at page 44 [0.1 g polymer dissolved in 100 ml of concentrated sulfuricacid at 25° C.].

If desired, the molecular weight of the polymer, the degree of branchingand amount of gelation can be controlled by the use of, for example,capping agents as described in U.S. Pat. No. 4,247,682 to Dahl, thedisclosure of which is incorporated herein by reference. The molecularweight of the polymer can also be controlled by a polymerizationreaction utilizing a two-monomer system as described above, by employinga slight excess of one of the monomers.

Capping agents, when employed, are added to the polymerization reactionmedium to cap the polymer on at least one end of the polymer chain. Thisterminates continued growth of that chain and controls the resultingmolecular weight of the polymer, as shown by the inherent viscosity ofthe polymer. Judicious use of the capping agents results in a polymerwithin a selected narrow molecular weight range, decreased gel formationduring polymerization, and decreased branching of the polymer chains andmelt stability. Both nucleophilic and electrophilic capping agents areused to cap the polymer at each end of the chain.

Preferred nucleophilic capping agents are 4-chlorobiphenyl,4-phenoxybenzophenone, 4-(4-phenoxyphenoxy)benzophenone, biphenyl4-benzenesulfonylphenyl phenyl ether, and the like.

Typical electrophilic capping agents are compounds of the formula##STR12## wherein Ar" is phenyl, 3-chlorophenyl, 4-chlorophenyl,4-cyanophenyl, 4-methylphenyl or other aromatic group substituted withan electron withdrawing substituent and E is halogen or other leavinggroup. Preferred electrophilic capping agents include benzoyl chloride,benzenesulfonyl chloride and the like.

As mentioned above, a key aspect of this invention is that the Lewisand/Lewis base complex solubilizes or solvates the polymer so that itremains in the reaction medium in a form capable of sustaining continuedpolymerization so that the desired high molecular weight is obtained ina controlled and reproducible fashion. Lewis acid is also present in thereaction medium as the catalyst for the Friedel-Crafts polymerizationreaction. The resulting polymer contains Lewis acid complexed to thecarbonyl groups of the polymer. For many polymerizations, the Lewis acidis complexed to substantially all the carbonyl groups in the polymer. Asis well known with polymers of this type, the catalyst residue must beremoved, i.e. the Lewis acid must be decomplexed from the polymer andremoved. A method for removing the catalyst residue is described in U.S.Pat. No. 4,237,884 to Dahl, the disclosure of which is incorporatedherein by reference.

Decomplexation can be accomplished by treating the polymerizationreaction mixture with a decomplexing base after completion ofpolymerization. The base can be added to the reaction medium or thereaction medium can be added to the base. The decomplexing base must beat least as basic towards the Lewis acid as the basic groups on thepolymer chain. such decomplexation should be effected before isolationof the polymer from the reaction mixture.

The amount of decomplexing base used should be in excess of the totalamount of bound (complexed) and unbound Lewis acid present in thereaction mixture and is preferably twice the total amount of Lewis acid.Typical decomplexing bases which can be used include water, diluteaqueous hydrochloric acid, methanol, ethanol, acetone,N,N-dimethylformamide, N,N-diemethylacetamide, pyridine, dimethyl ether,diethyl ether, tetrahydrofuran, trimethylamine, trimathylaminehydrochloride, dimetyl sulfide, tetramethylanesulfone, benzophenone,tetramethylammonium chloride, isopropanol and the like. The decomplexedpolymer can then be removed by conventional techniques such as adding anonsolvent for the polymer which is a solvent for or miscible with therest of the reaction mixture including the base-catalyst complex;spraying the reaction medium into a non-solvent for the polymer;separating the polymer by filtration; or evaporating the volatiles fromthe raction medium and then washing with an appropriate solvent toremove any remaining base/catalyst complex from the polymer.

In recovery of the polymer from the reaction mixture, the reactionmixture can be liquified, if desired by the method described in U.S.Pat. No. 4,6556151 (1987) of R. Reamey, the disclosure of which isincorporated herein by reference.

The following examples illustrate the process of this invention using avariety of Lewis acids, Lewis bases, inert diluents and monomers. It isto be understood that other reactants and reaction media within thescope of the teaching of this invention can be employed, if desired.

EXAMPLE 1

A 500 ml 3 neck round bottom flask equipped with a stirrer, thermometer,and nitrogan inlet was charged with 1,4-diphenoxybenzene (13.2198 g0.0504 mole), terepthtaloyl chloride (10.1515 g 0.0500 mole), benzoylchloride (0.1124 g, 0.0008 mole)., sulfolane (27.04 g, 0.225 mole), andanhydrous methylene chloride (150 millimeters, ml). The atmosphereinside the flask was purged with and kept under nitrogen. The flask andits contents were cooled to -40° C. with a dry ice-acetone bath.Anhydrous aluminum chloride (49.7 g, 0.373 mole) was added over a 12minute period, with continued cooling. The stirred reaction mixture wasallowed to warm up to about 15° C. over a period of 1.5-2 hours. Thered, highly viscous mixture was then transferred to a glass tray undernitrogen, allowed to warm up to 20° C., and added portionwise to rapidlystirred methanol (Waring blender). The resulting fibrous polymer wascollected, washed with methanol, and soaked over night in more methanol.Following a second overnight soaking, this time in water, anothermethanol wash, and vacuum drying (120°-160° C.), there was obtained acolorless fibrous polymer (18.9 g, 96.3% yield).

Its inherent viscosity was 1.09 (0.1% solution in sulfuric acid).Compression molding at 400° C. for 3 min gave nearly colorless flexibleslabs of essentially unchanged inherent viscosity (1.10). Stress/strainanalysis of the slabs gave a Young's modulus of 216,700 psi, elongationat break of 80%, and tensile strength of 9,130 psi, as measured by ASTMD-638-80. Material extruded at 400° C. also exhibited no change ininherent viscosity (1.10).

EXAMPLE 2

To a 250 ml three neck round bottom flask equipped with a mechanicalstirrer, a nitrogen inlet, and a thermometer well fitted with a J-typethermocouple was added methylene chloride (30 ml, freshly distilled fromphosphorus pentoxide). The flask and its contents were purged with andkept under nitrogen and cooled to -27° C. with a dry ice-acetone bath.Anhydrous aluminum chloride (17.68 g, 132.6 mmole) was then added viaGooch tubing. To the resulting cold solution, N,N-dimethylformamide(DMF, 5.54 g, 75.8 mmole, freshly vacuum distilled from calcium hydride)in methylene chloride (15 ml) was added slowly (to control the vigorousexotherm). With continued cooling, a solution of 1,4-diphenoxybenzene(6.6811 g, 25.5 mmole), terephthaloyl chloride (5.1302 g, 25.3 mmole),and benzoyl chloride (0.571 g, 0.40 mmole) in methylene chloride (25 ml)was added. The transferring flask was rinsed with an additional volumeof methylene chloride (10 ml) to ensure complete transfer. The stirredreaction mixture was allowed to warm up to room temperature over a 6.3hour period, during which time it became a viscous orange-redsuspension. It was next cooled down to 5°-6° C. with an ice bath and thereaction was quenched with DMF (50 ml). At this time, the polymerizationmixture became a highly viscous white slurry. The polymer was isolatedby filtration, transferred into a 1 qt. glass blender containing cold(0° C.) DMF (100 ml), and blended at high speed until room temperaturewas reached. This process was repeated. The polymer was then digestedtwice in DMF (250 ml, 50° C., 24 hrs), once in water (300 ml, roomtemperature, 24 hours), and once in hydrochloric acid (0.5 M, 500 ml,room temperature, 24 hours). After washing with more water and vacuumdrying, polymer (8.9g, 90% yield) of inherent viscosity 1.2 (0.1% insulfuric acid) was obtained. Its melt stability and processability weredemonstrated by the fact that slabs pressed for 30 min at 400° C. showedminimal change in inherent viscosity.

EXAMPLE 3

The procedure of Example 2 was repeated using terephthaloyl chloride(5.17 g, 25.2 mmole), 1,4-diphenoxybenzene (6.56 g. 25.0 mmole) and4-(4-phenoxyphenoxy)benzophenone (0.1466 g, 0.4 mmole).

The resultant polymer had an inherent viscosity of 1.25. Polymer pressedfor 30 minutes at 400° C. gave slabs of inherent viscosity 1.34 (averageof 2 samples). Pressing at 410° C. for 30 minutes gave slabs of inherentviscosity 1.71 (average of 3 samples), with a slight amount of gel.

EXAMPLE 4

The procedure of Example 2 was repeated using purified aluminumchloride. The initial temperature employed was -15° C. and the reactionmixture was allowed to warm up to 8° C. The aluminum chloride waspurified prior to introduction into the reaction medium by vacuumdistillation from a mixture of 1500 g aluminum chloride, 100 g sodiumchloride and 5 g aluminum powder followed by vacuum sublimation.

The polymer thus obtained had an inherent viscosity of 1.17 (average of2 samples). Slabs pressed at 400 ° or 410° C. for 30 minutes hadinherent viscosities of 1.15 (average of 4 samples) and 1.18 (average of4 samples), respectively. No gel was observed in any of the slabs.

EXAMPLE 5

A reaction flask equipped with a magnetic stirrer and purged withnitrogen and charged with methylene chloride (8 ml) was cooled in an icebath. To it was added n-butyronitrile (1.382 g, 0.020 mmole) followed byaluminum chloride (6.56 g, 0.050 mmole). The latter was added slowlybecause of the vigorous exotherm generated. When this addition wascompleted, p-phenoxybenzoyl chloride (2.33 g, 0.010 mmole) was added,also gradually. Polymerization was allowed to proceed overnight (about16 hours) at room temperature. The polymer was recovered by transferringthe polymerization mixture into methanol (about 100 ml), breaking it upin a blender at high speed, filtering, and washing generously withmethanol. After digesting overnight in more methanol (about 100 ml) atroom temperature, the polymer was washed with water and vacuum dried(120°-160° C.). The product was a white polymer of inherent viscosity1.69. When compression molded at 400° C. for 3 min, it formed atransparent yellow, tough, flexible slab.

EXAMPLE 6

Example 5 was repeated, but with the Lewis bases (0.020 mmole) given inTable I in place of the n-butyronitrile.

                  TABLE I                                                         ______________________________________                                                              Inherent   Slab (3 min,                                 Lewis Base    Color   Viscosity  400° C.)                              ______________________________________                                        Dimethyl sulfide                                                                            White   0.79       Tough, flexible,                                                              yellow                                       1-Nitropropane                                                                              White   0.57       Tough, flexible,                                                              l. tan                                       Pyridine N-oxide                                                                            L. pink 2.5**      Tough, flexible,                                                              l. tan                                       Isoquinoline  L. pink 0.84       Tough, flexible,                                                              l. tan                                       Methylamine   White   0.40       Brittle, l. tan                              hydrochloride                                                                 1-Ethylpyridinium                                                                           L. pink 2.50**     Tough, flexible,                             bromide                          l. pink                                      Triphenyl phosphine                                                                         L. pink 0.50 (some***                                                                            Flexible, l. tan                             oxide                 gel)                                                    *Diethylamine --      0.77       Tough, flexible                              hydrochloride                                                                 *Diethyl ether                                                                              --      0.80       Tough, flexible                              *Imidazole    --      1.79       Tough, flexible                              Acetone       White   0.73       Tough, flexible                              Methyl Acetate                                                                              White   (some gel)***                                                                            Tough, flexible                              N,N-Dimethylformamide                                                                       White   1.82       Tough, flexible                              Tetramethylammonium                                                                         White   0.82       Tough, flexible                              chloride                                                                      ______________________________________                                         *Run on the scale corresponding to 0.006 mmole pphenoxybenzoyl chloride.      **The high inherent viscosity indicates production of high molecular          weight polymer. Use of capping agents so described above would yield a        polymer in the desired molecular weight range.                                ***The presence of gel indicates crosslinking has occurred. The inherent      viscosity measurement reflects the molecular weight of the uncrosslinked      portion of the polymer product.                                          

EXAMPLE 7

Example 5 was repeated, except that o-dichlorobenzene was used in placeof the methylene chloride. The resultant polymer was light yellow andhad an inherent viscosity of 1.12. It could be pressed at 400° C. into atough, flexible, pale yellow slab.

EXAMPLE 8

Example 5 was repeated, except that DMF was substituted forn-butyronitrile and o-difluorobenzene for methylene chloride. Theresultant polymer was light yellow and had an inerent viscosity of 1.18.It could be pressed into a tough, flexible, pale yellow slab.

EXAMPLE 9

Example 5 was repeated, except that DMF was substituted forn-butyronitrile and 1,2,4-trichlorobenzene for methylene chloride. Theresultant polymer was white and had an inherent viscosity of 1.50. Itcould be pressed into a flexible, light colored slab.

EXAMPLE 10

Diphenyl ether (1.7025 g, 0.010 mole) was polymerized with terephthaloylchloride (1.6242 g, 0.008 mole) and isophthaloyl chloride (0.04058 g,0.002 mole) in the presence of methylene chloride (14 ml),trimethylamine hydrochloride (2.19 g, 0.023 mole), and aluminum chloride(6.0 g, 0.045 mole) by the procedure described in example 5. Theresultant polymer had an inherent viscosity of 0.74. It could be pressedinto a slab that was light colored and flexible.

EXAMPLE 11

The N-succinimido derivative of p-phenoxybenzoic acid (1.200 g, 0.004mole) was polymerized in methylene chloride (6 ml), trimethylaminehydrochloride (1.50 g, 0.016 mole), and aluminum chloride (4.40 g, 0.033mole) according to the procedure in example 5. The resulting polymer hadan inherent viscosity of 0.95 and could be pressed into a flexible tanslab.

EXAMPLE 12

A suspension of lithium chloride (0.84 g, 0.0198 mole) and aluminumchloride (5.40 g, 0.0405 mole) in 1,2-dichloroethane (7.0 ml) wasstirred under nitrogen in a sealed reaction tube for 40 minutes. To theresulting solution was added p-phenoxybenzoyl chloride (2.20 g, 0.00945mole). Polymerization was permitted to continue for about 90 minutes toyield a highly viscous solution. 1,2-dichloroethane (4 ml) was added todilute the reaction mass. The polymer was recovered by decomplexation ofthe mixture with water in a Waring blender, washing with awater/methanol solution, soaking the product in water overnight, thenwashing with methanol and drying. The product was a colorless polymerhaving an inherent viscosity of 1.58. When compression molded at 400° C.for 2 minutes, it formed a pale yellow, tough, flexible slab.

EXAMPLE 13

A 500 ml 3-neck round bottom flask equipped with a stirrer, thermometerand nitrogen inlet was charged with N,N-dimethylformamide (16.45g,0.2250 mole) and anhydrous methylene chloride (150 ml). The atmosphereinside the flask was purged with and kept under nitrogen. The flask andits contents were cooled to -30° C. with a dry ice-acetone bath.Anhydrous aluminum chloride (75.30 g, 0.5647 mole), followed by4,4'-diphenoxybenzophenone (18.3940 g, 0.05020 mole), terephthaloylchloride (10.1510 g, 0.0500 mole) and benzoyl chloride (0.0493 g, 0.3500mmole) were added with continued cooling. The transferring flasks wererinsed with anhydrous methylene chloride (50 ml total) to ensurecomplete transfer. The stirred reaction mixture was allowed to warm upto 0° C. in 15 minutes and to 21° C. in 1.5 hours. Part of the viscousreaction mixture was added portionwise to rapidly stirred methanol(Waring blender). The resulting fibrous polymer was collected, washedwith methanol and vacuum dried (120° -160° C.). Its inherent viscositywas 1.28 (0.1% in sulfuric acid). The remaining part of the viscousreaction mixture was added portionwise to rapidly stirred 10%hydrochloric acid (Waring blender). The fibrous polymer obtained waswashed with water, then refluxed 15 minutes in N,N-dimethylacetamide,washed with water and vacuum dried (120°-160° C.). Its inherentviscosity was 1.37. A compression molded slab pressed at 400° C. for 20minutes showed an inherent viscosity of 1.40, indicating melt stability.Its processability was further demonstrated by extrusion at 400° C.through a mini-extruder to give a light tan, flexible and smooth strandof extrudate of 1.42 inherent viscosity.

EXAMPLE 14

A 50 ml 3 neck round bottom flask equipped with a stirrer, thermometerand nitrogen inlet was charged with aluminum trichloride (6.29 g, 0.0472mole) and lithium chloride (1.00 g, 0.0236 mole) in 1,2-dichloroethane(17 ml) was cooled to 0° C. in an ice-acetone bath. Diphenyl ether (2.01g, 0.0118 mole) and phosgene (2.80 g, 0.0283 mole) were then added. Thebath was removed and the reaction mixture was permitted to warm to roomtemperature (24° C.). The mixture was stirred at 24° C. for 23 hours. Aclear deep red viscous mass formed. Additional diphenyl ether (0.060 g6×10⁻⁴ mole) was then added and the reaction mixture stirred for 2hours. The reaction mass was added to cold methanol (Waring blender),filtered and the precipitate was washed in methanol overnight thensoaked in water. The mixture was filtered, rinsed with methanol anddried under vacuum at 120° C. The resulting polymer (2.15 g, 92% yield)was an off-white powder having an inherent viscosity of 0.60 (0.1% inconcentrated sulfuric acid).

Compression molding at 400° C. yielded a light colored, tough, flexibleslab. The slab became brittle on annealing.

EXAMPLE 15

The procedure of Example 15 was repeated using4,4'-diphenoxybenzophenone (2.162 g, 0.0059 mole), phosgene (1.43 g,0.0144 mole), lithium chloride (1.00 g, 0.0236 mole) and aluminumtrichloride (6.24 g, 0.0468 mole) in 1,2-dichloroethane (8 ml). Theresulting product (2.2 g, 94% yield) was an off-white polymer having arelatively high gel content which formed a yellow flexible slab whenpressed at 400° C.

The preparation of aromatic polymers in accordance with this inventionhas been set forth above with reference to specific embodiments thereof.It is to be understood that the specific embodiments are illustrative innature and the invention is not limited to such embodiments. Theinvention in its broadest aspect is directed to an electrophilicpolymerization reaction in which the reaction medium comprises freeLewis acid and a complex between a Lewis acid component and a Lewis basecomponent and, optionally, a diluent.

EXAMPLE 16

Procedure A: N,N-Dimethylformamide (DMF, 1.45 g, 0.020 mole) was addeddropwise with cooling and stirring to anhydrous aluminum chloride (5.70g, 0.043 mole). An exotherm ensued, leading to a hot, fluid melt with afew suspended aluminum chloride particles. The fluid was kept at100°-110° C. for 5-10 minutes under nitrogen. Upon cooling, a lightcolored liquid was obtained, apparently containing some stillundissolved aluminum chloride. p-Phenoxybenzoyl chloride (3.00 g, 0.013mole) was added with stirring. The entire mixture was heated accordingto the schedule in the accompanying table, cooled, and worked up byprecipitating into methanol, washing with water and methanol, anddrying.

Procedure B: The reaction was carried out as above, but with thefollowing amounts of chemicals: DMF (1.46 g, 0.02 mole), anhydrousaluminum chloride (5.32 g, 0.040 mole), and p-phenoxybenzoyl chloride(1.60 g, 0.007 mole). The polymerization mixture was not heated, but wasinstead maintained at room temperature for the times indicated.

Results are given inthe table below. Inherent viscosities reported arethose of the polymer as obtained, and not of the slabs. Slabs, if noted,were pressed at 400° C. for 3 minutes.

                  TABLE II                                                        ______________________________________                                        Pro-  Time/Temp.     Inh.                                                     cedure                                                                              Profile        Visc.  Comments                                          ______________________________________                                        B     62 hr/24° C.                                                                          1.46   Flexible yellow-red slab                          B     17 hr/24° C.                                                                          0.57   Light colored polymer                             A     15 min/24° C. and                                                                     1.14   Pale yellow polymer; light                              10 min/100-20° C.                                                                            colored, flexible slab                            A     1 hr/24° C. and                                                                       0.86   Colorless crystalline slab                              15 min/100° C.                                                   A     5 min/24° C.,                                                                         0.73   Light tan flexible slab                                 5 min/80-100° C.,                                                      5 min/150-70° C.,                                                      and 2 min/170-80° C.                                             ______________________________________                                    

EXAMPLE 17

A stock solution was prepared from p-phenoxybenzophenone (0.6165 g,0.00225 mole), benzoyl chloride (0.3032 g, 0.00215 moles), dichlorethane(63.6 g), and p-phenoxybenzoyl chloride (116.2 g, 0.400 mole) and storedat room temperature in a flask stoppered with an-air/no-air septum. Thisstock solution was sufficient for about twenty polymerizations of thescale below. Polymer prepared from this stock solution is double-cappedat 0.6 mole % (calculated from the ratio of p-phenoxybenzophenone, thelimiting capping agent, to p-phenoxybenzoyl chloride).

A reactor consisting of 200 ml resin kettle and a top with four openingsto which were attached a mechanical stirrer with a PTFE paddle, a 50 mladdition funnel, a glass-clad thermocouple probe and an inert gas supplytube was assembled. (Glass equipment was dried at 100° C. until justprior to use.) All ground glass joints were sealed with PTFE seals,except for the stirrer shaft which was sealed with vacuum grease. Theassembled reactor was dried with a hot air fun or Bunsen burner whilebeing flushed with nitrogen or argon. The inert gas atomosphere wasmaintained throughout the operations except for momentary interruptionsfor the addition of reagents.

The reactor was charged with, in order, anhydrous aluminum chloride(10.0 g, 0.075 mole, Witco #0099), lithium chloride (1.59 g, 0.0375mole, ACS Reagent Grade), and 1,2-dichloroethane (10.0 g). The whiteslurry was cooled to between 015° and -25° C. with a dry ice/acetonebath.

Monomer stock solution (9.04 g) was added dropwise over a 7 min, withcontinued stirring and cooling. After the completion of this addition,the reaction mixture's temperature was maintained at -15° C. for onehour and then raised to 0° C. and maintained there for 23 hours.Approximately 2-3 hours after addition of the monomers, a notableincrease in viscosity occurred. At this point stirring became extremelydifficult and was usually discontinued.

The polymer could be isolated by one or two workup procedures:

(A) The reaction mixture was transferred into a 500 ml Waring blendercontaining DMF (100-200 ml) chilled to -40° C. The blender was turned onand the dark orange gel transformed into a white, decomplexed polymer.The polymer was collected by filtration, washed with DMF (100 ml),digested in DMF (100 ml, 50° C., overnight), filtered, and digested inwater (2×150 ml, 60° C., 1 hr each). After filtration, the polymer wasdried overnight at 165° C. in a vacuum oven.

(B) The reaction mixture was transferred into a 500 ml Waring blendercontaining 2% aqueous hydrochloric acid (200 ml) at room temperature.The blender was turned on and the dark orange gel transformed intowhite, decomplexed polymer. The polymer was collected by filtration,washed with 2% aqueous hydrochloric acid (200 ml) and digestedsuccessively in methanol (200 ml, overnight, 40° C.) and in hot 2%aqueous hydrochloric acid (2×200 ml, 1 hr each). After filtration, thepolymer was washed with deionized water (500 ml) and dried overnight at165° C. in a vacuum oven.

A white fluffy polymer with inherent viscosity 1.1-1.2 dl/g wasobtained. The inherent viscosity did not change by more than 0.10 dl/gafter 30 min at 400° C.

EXAMPLE 18

This example demonstrates the suppression of undesirable side reactionsby polymerization in the presence of a Lewis base (in this case, lithiumchloride). Two polymerizations were performed, employing the procedureof Example 17, workup B, with the following exceptions: (1) the cappinglevel was 0.45 mole %, (2) the time-temperature profile was 1 hr/0° C.followed by room temperature reaction, and (3) one of the reactions wasrun without lithium chloride. Aliquots were taken out at the timesindicated in the accompanying table and figure, worked up, and analyzed.

While the reaction with lithium chloride responds as expected to cappingand achieves stable molecular weight after about fifteen hours, the onewithout lithium chloride does not respond to capping, but instead keepsincreasing in molecular weight, indicating the occurrence of substantialside reactions. The polymer from the lithium chloride reaction was moremelt stable.

                  TABLE III                                                       ______________________________________                                        Polymer Inherent Viscosity After Time                                         at 400° C. (min)                                                       Reaction                                                                      Time (hrs)  0      5           30   60                                        ______________________________________                                        With Lithium Chloride                                                         6           1.08   1.08        1.24 1.19                                      8           1.09   1.12        1.15 1.30                                      10          1.11   1.14        1.12 gel                                       13          1.20   --          1.35 --                                        26          1.32   1.24        1.36 1.18                                      32          1.33   1.34        1.32 gel                                       Without Lithium Chloride                                                      6           0.93   0.94        --   1.09                                      8           1.02   1.00        0.97 gel                                       10          1.05   1.13        1.18 gel                                       13          1.15   1.12        1.12 gel                                       26          1.72   --          gel  --                                        32          2.15   --          gel  --                                        ______________________________________                                    

EXAMPLE 19

The procedure of Example 17, workup A, was followed, with theseexceptions: (1) p-phenoxybenzophenone (0.45 mole %) was the only cappingagent and (2) the amount of 1,2-dichloroethane was adjusted to achievethe indicated per cent loading. For the purposes of this example, "percent loading" is defined as 100 times the ratio of the theoretical yield(in grams) of polymer to the sum (in grams) of monomer, capping agent,Lewis acid, Lewis base, and solvent in the reaction mixture.

The results are tabulated below showing the effect of monomerconcentration on inherent viscosity of the polymer.

                  TABLE IV                                                        ______________________________________                                               Percent                                                                              Polymer                                                                Loading                                                                              Inh. Visc.                                                      ______________________________________                                               5      0.51                                                                   10     0.80                                                                   12     1.00                                                                   14     1.11                                                                   16     1.15                                                                   18     1.18                                                                   20     0.90                                                            ______________________________________                                    

EXAMPLE 20

p-Phenoxybenzoyl chloride was polymerized as described in Example 17,workup B, except that no lithium chloride was used andp-phenoxy-benzophenone (0.45 mole %) was the only capping agent used.The results are provided in the table below which illustrate the effectof the amount of aluminum chloride on the inherent viscosity of thepolymer.

                  TABLE V                                                         ______________________________________                                        Molar Ratio of   Polymer                                                      Aluminum Chloride                                                                              Inherent                                                     to Monomer       Viscosity                                                    ______________________________________                                        1.20             0.50                                                         1.50             0.98                                                         1.80             1.13                                                         2.00             1.17                                                         3.00             1.15                                                         ______________________________________                                    

A comparison polymerization run with aluminum chloride: lithiumchloride:p-phenoxybenzoyl chloride molar ratio of 3.0:1.5:1.0 gave aninherent viscosity of 1.15.

EXAMPLE 21

A reaction flask equipped with a magnetic stirrer and a nitrogen inletwas charged with methylene chloride (8 mL) and N,N-dimethylformamide(1.45 g, 20 mmol). Anhydrous aluminum bromide (13.33 g, 50 mmol) wasadded gradually, with cooling (exotherm ensues), followed byp-phenoxybenzoyl chloride (2.33 g, 10 mmol). Polymerization was allowedto proceed overnight at room temperature. The polymer was isolated byprecipitating it into methanol and washing overnight at room temperatureconsecutively with methanol and water.

The polymer was a white powder with inherent viscosity 1.03. A slabpressed at 400° C. for 5 minutes was transparent and flexible.

EXAMPLE 22

p-Phenoxybenzoyl chloride was polymerized as in Example 17, workup A,except that (1) p-phenoxybenzophenone (0.45 mole %) was the only cappingagent, (2) the "per cent loading" was adjusted to the levels given belowby varying the amount of 1,2-dichloroethane used, and (3) no Lewis basewas added. For the purposes of this example "per cent loading" isdefined as 100 times the ratio of the theoretical yield (in grams) ofpolymer to the sum (in grams) of monomer, capping agent, Lewis acid, andsolvent. The results are provided in the table below.

                  TABLE VI                                                        ______________________________________                                        Percent        Inherent                                                       Loading (%)    Visc. (dl/g)                                                   ______________________________________                                        5              0.65-0.75                                                      10             0.84-1.01                                                      16             1.10-1.20                                                      ______________________________________                                    

EXAMPLE 23

Diphenyl ether 4,4'-dicarbonyl dichloride was polymerized with diphenylether according to the procedure of Example 17, workup B, except that(1) the monomers were added directly to the reactor, instead of from astock solution, (2) the equivalent ratio of aluminum chloride to acidhalide groups was 2.0, (3) no lithium chloride was used, and (4) nocapping agents were used.

The polymer obtained an inherent viscosity of 1.03.

EXAMPLE 24

Diphenyl ether 4,4'-dicarbonyl dichloride was polymerized with1,4-diphenoxybenzene according to the procedure of Example 17, workup B,except that (1) the monomers were added directly to the reactor, insteadof from a stock solution, (2) the equivalent ratio of aluminum chlorideto acid halide groups was 2.0, (3) no lithium chloride was used, and (4)no capping agents were used.

The polymer obtained had an inherent viscosity of 0.93.

EXAMPLE 25

4,4'-Diphenoxybenzophenone was polymerized with terephthaloyl chloride,with and without added lithium chloride, according to the procedure ofExample 17, workup A, with these exceptions: (1) the reactions were notcapped; (2) aluminum chloride was added to a suspension of the monomersin 1,2-dichloroethane, instead of vice-versa; (3) where lithium chloridewas used, it was used in the amount of 2.0 equivalents per equivalent ofcarbonyl groups in the reaction mixture; and (4) aluminum chloride wasused in a 10 equivalent % excess over the total equivalents of carbonylgroups and lithium chloride.

The reaction with lithium chloride gave polymer with inherent viscosity5.2 and the one without, 4.2. But samples contained some gel.

EXAMPLE 26

This example demonstrates the necessity for controlling the excess ofaluminum chloride where the monomers used are terephthaloyl chloride anda comonomer as defined in I(ii)(a), I(ii)(b), or I(i)(d) and where thepolymerization is conducted in the substantial absence of Lewis base.

Terephthaloyl chloride was polymerized with 1,4-diphenoxybenzene by theprocedure of Example 17, workup A, with these exceptions: (1) no cappingagents were employed, (2) the "per cent loading," as definedhereinbefore, was about 12% (Example 17 calculates to about 16), (3) nolithium chloride was added, and (4) the equivalent % excess of aluminumchloride was either 10 or 100, relative to the total equivalents of acidchloride groups present.

The reaction with only 10 equivalent % excess aluminum chloride gavepolymer with inherent viscosity 1.59. The reaction with 100 equivalent %excess aluminum chloride gave polymer with inherent viscosity 0.18.

EXAMPLE 27

This example demonstrates the benefits of polymerizing terephthaloylchloride with a comonomer as defined in I(ii)(a), I(ii)(b), or I(ii)(c)in the presence of a Lewis base.

Terephthaloyl chloride was polymerized with 1,4-diphenoxybenzene withand without lithium chloride added, according to the procedure ofExample 17, workup A, with exceptions as noted: (1) the "percentloading," as defined hereinbefore, was about 12%, (2) thepolymerizations were capped by employing 0.8 mole % excess of1,4-diphenoxybenzene and 0.16 mole % of benzoyl chloride, (3) wherelithium chloride was added, it was in the amount of 1 equivalent perequivalent of acid halide groups, and (4) the equivalent % excess ofaluminum chloride over the sum of acid halide and lithium chlorideequivalents was 10%.

The reaction with lithium chloride was homogeneous and gave polymer withinherent viscosity 0.91, while one without lithium chloride washeterogeneous and gave polymer of inherent viscosity 0.60.

We claim:
 1. A method of producing a poly(arylene ether ketone) whichcomprises polymerizing a monomer system comprising:(I) (i) phosgene oran aromatic diacid dihalide together with (ii) a polynuclear aromaticcompound containing two active hydrogen atoms or(II) a polynucleararomatic compound containing both an acid halide group and an activehydrogen; in a reaction medium wherein Lewis base is substantiallyabsent, comprising: (A) a Lewis acid in an amount of substantially oneequivalent per equivalent of carbonyl groups present, plus an amounteffective to act as a catalyst for the polymerization, and (B) anon-protic diluent in an amount from 0 to 93% by weight based on theweight of the total reaction mixture;wherein (a) when the monomer systemis (I) and compound (I)(ii) contains an undeactivated aryloxy group:(aa)the Lewis acid is present in excess of the minimum amount specified in(A) above by an amount of up to 0.8 equivalents per equivalent ofundeactivated aryloxy groups present, and, if the acid halide groups aresituated on separate non-fused aromatic rings, by an additional amountof up to 0.5 equivalents per equivalent of acid halide groups; and (bb)the concentration of monomers in the reaction mixture is at least 7% byweight, based on the total weight of the reaction mixture; with thefurther proviso that when the diacid dihalide (I)(i) is benzenedicarbonyl dichloride or diphenyl ether dicarbonyl dichloride andcompound (I)(ii) is H--Ar--O--Ar--H wherein each Ar is independentlyselected from substituted or unsubstituted phenylene and substituted orunsubstituted polynuclear aromatic moieties free from ketone carbonyland ether oxygen groups, the polymer produced is at least partiallycrystalline; (b) when the monomer system is (II) and contains anundeactivated aryloxy group, the Lewis acid is present in excess of theminimum specified in (A) above by an amount of up to 0.8 equivalent perequivalent of undeactivated aryloxy groups in the monomers; and (c) whenthe monomer system is either (I) or (II) and does not contain anyundeactivated aryloxy groups, the Lewis acid is present in an amount inexcess of the minimum specified in (A) above by at least 0.6+[0.25×tanh(50(0.1-D))]equivalents per equivalent of acid halidegroups, where D is the molar ratio of monomer to diluent.
 2. A method ofproducing a poly(arylene ether ketone) which comprises polymerizing amonomer system comprising:(I) (i) phosgene or an aromatic diaciddihalide together with (ii) a polynuclear aromatic comonomer selectedfrom the group consisting of:(a) H--Ar--O--Ar--H, (b) H--(Ar--O)_(n)--Ar--H, wherein n is 2 or 3, (c) H--Ar--O--Ar--(CO--Ar--O--Ar)_(m) --H,wherein m is 1, 2, or 3, and (d) H--(Ar--O)_(n)--Ar--CO--Ar--(O--Ar)_(m) --H, wherein m and n are as hereinabovedefined; (II) an acid halide of the formula:

    H--Ar--O--[(Ar--CO).sub.p --(Ar--O).sub.q --(Ar--CO).sub.r ].sub.k --Ar--CO--Z,

wherein Z is halogen; k is 0, 1, or 2; p is 1 or 2; q is 0, 1, or 2; andr is 0, 1, or 2; or (III) an acid halide of the formula:

    H--(Ar--O).sub.n --Ar--Y,

wherein Y is CO--Z or CO--Ar--CO--Z and n and Z are as hereinabovedefined;wherein each Ar is independently selected from substituted orunsubstituted phenylene, and substituted or unsubstituted polynucleararomatic moieties free of ketone carbonyl and ether oxygen groups; in areaction medium wherein Lewis base is substantially absent, comprising:(A) a Lewis acid in an amount of substantially one equivalent perequivalent of carbonyl groups present, plus an amount effective to actas a catalyst for the polymerization, and (B) a non-protic diluent in anamount from 0 to 93% by weight, based on the weight of the totalreaction mixture;wherein (i) when the monomer system includes a diaciddihalide and a comonomer as defined in (I)(ii)(a), (I)(ii)(b) or(I)(ii)(d) above:(aa) the Lewis acid is present in excess of the minimumspecified in (A) above by an amount of up to 0.8 equivalents perequivalent of undeactivated aryloxy groups in the monomers, and, if theacid halide groups are situated on separate non-fused aromatic rings, byan additional amount of up to 0.5 equivalents per equivalent of acidhalide groups, and (bb) the concentration of monomers in the reactionmixture is at least 7% by weight, based on the total weight of thereaction mixture; with the further proviso that when the monomer systemincludes a comonomer as defined in (I)(ii)(a) and the diacid dihalide isbenzene dicarbonyl dichloride or diphenyl ether dicarbonyl dichloride,the polymer produced is at least partially crystalline; or (ii) when themonomer system is III, the Lewis acid is present in excess of theminimum specified in (A) above by an amount of up to 0.8 equivalent perequivalent of undeactivated aryloxy groups in the monomers; or (iii)when the monomer system is (II) or (I)(i) together with (I)(ii)(c), theLewis acid is present in an amount in excess of the minimum specified in(A) above by at least
 0. 6+[0.25×tanh(50(0.1-D))]equivalents perequivalent of acid halide groups, where D is the molar ratio of monomerto diluent.
 3. A method in accordance with claim 1 or 2, wherein theLewis acid is selected from the group consisting of aluminumtrichloride, boron trichloride, aluminum tribromide, titaniumtetrachloride, antimony pentachloride, ferric chloride, galliumtrichloride, and molybdenum pentachloride.
 4. A method in accordancewith claim 3, wherein the Lewis acid is aluminum trichloride.
 5. Amethod in accordance with claim 3, wherein the Lewis acid is aluminumtribromide.
 6. A method in accordance with claim 1 or 2, wherein thepolymerization is carried out in the presence of a non-protic diluent.7. A method in accordance with claim 6, wherein the diluent has adielectric constant of at least about 2.5 at 24° C.
 8. A method inaccordance with claim 6, wherein the diluent has a dielectric constantin the range of from about 4.0 to about 25 at 24° C.
 9. A method inaccordance with claim 6, wherein the diluent is selected from the groupconsisting of methylene chloride, carbon disulfide, o-dichlorobenzene,1,2,4-trichlorobenzene, o-difluorobenzene, 1,2-dichloroethane,1,2,3,4-tetrachloroethane, and tetrachloroethylene.
 10. A method inaccordance with claim 1 or 2, wherein a capping agent is added to thereaction medium.
 11. A method in accordance with claim 10, wherein botha nucleophilic and an electrophilic capping agent are added to thereaction medium.
 12. A method in accordance with claim 11, wherein thenucleophilic capping agent is selected from the group consisting of4-chlorobiphenyl, 4-phenoxybenzophenone, biphenyl,4-(4-phenoxyphenoxy)benzophenone, and 4-benzenesulfonylphenyl phenylether.
 13. A method in accordance with claim 11, wherein theelectrophilic capping agent is selected from the group consisting ofbenzoyl chloride and benzenesulfonyl chloride.
 14. A method inaccordance with claim 2, wherein the monomer system comprises phosgeneor an aromatic diacid dihalide together with a polynuclear aromaticcomonomer of the formula

    H--Ar--O--Ar--H


15. A method in accordance with claim 14, wherein the monomer systemcomprises terephthaloyl or isophthaloyl chloride or mixtures thereof anddiphenyl ether.
 16. A method in accordance with claim 14, wherein theLewis acid is aluminum trichloride.
 17. A method in accordance withclaim 14, wherein the concentration of monomers in the reaction mediumis at least about 10% based on the total weight of the reaction mixture.18. A method in accordance with claim 14, wherein the concentration ofthe monomers in the reaction medium is at least about 15% by weightbased on the total weight of the reaction mixture.
 19. A method inaccordance with claim 14, wherein the polymerization is conducted at atemperature in the range of -30° C. to +25° C.
 20. A method inaccordance with claim 2, wherein the monomer system comprises phosgeneor an aromatic diacid dihalide together with a polynuclear aromaticcomonomer of the formula

    H--(Ar--O).sub.n --Ar--H


21. A method in accordance with claim 20, wherein the monomer systemcomprises terephthaloyl chloride and 1,4-diphenoxybenzene.
 22. A methodin accordance with claim 20, wherein the Lewis acid is aluminumtrichloride.
 23. A method in accordance with claim 20, wherein theconcentration of the monomers in the reaction medium is at least about10% based on the total weight of the reaction mixture.
 24. A method inaccordance with claim 20, wherein the concentration of monomers in thereaction medium is at least about 15% by weight based on the totalweight of the reaction mixture.
 25. A method in accordance with claim20, wherein the polymerization is conducted at a temperature in therange of -30° to +25° C.
 26. A method in accordance with claim 2,wherein the monomer system comprises phosgene or an aromatic diaciddihalide together with a polynuclear aromatic comonomer of the formula

    H--Ar--O--Ar--(CO--Ar--O--Ar).sub.m --H


27. A method in accordance with claim 26, wherein the monomer systemcomprises terephthaloyl chloride and 1,4-diphenoxybenzophenone.
 28. Amethod in accordance with claim 26, wherein the Lewis acid is aluminumtrichloride.
 29. A method in accordance with claim 26, wherein theconcentration of the monomers in the reaction medium is at least about10% based on the total weight of the reaction mixture.
 30. A method inaccordance with claim 26, wherein the polymerization is conducted at atemperature in the range of -30° to +25° C.
 31. A method in accordancewith claim 2, wherein the monomer system comprises phosgene or anaromatic diacid dihalide together with a polynuclear aromatic comonomerof the formula

    H--(Ar--O).sub.n --Ar--CO--Ar--(O--Ar).sub.m --H


32. A method in accordance with claim 31, wherein the monomer systemcomprises phosgene and bis(phenoxyphenoxy)benzophenone.
 33. A method inaccordance with claim 31, wherein the Lewis acid is aluminumtrichloride.
 34. A method in accordance with claim 31, wherein theconcentration of monomers in the reaction medium is at least about 10%by weight based on the total weight of the reaction mixture.
 35. Amethod in accordance with claim 31, wherein the concentration ofmonomers in the reaction medium is at least about 15% by weight based onthe total weight of the reaction mixture.
 36. A method in accordancewith claim 31, wherein the polymerization is conducted at a temperaturein the range of -30° to +25° C.
 37. A method in accordance with claim 2,wherein the monomer system comprises an acid halide of the formula

    H--Ar--O--[(Ar--CO).sub.p --(Ar--O).sub.q --(Ar--CO).sub.r ].sub.k --Ar--CO--Z


38. A method in accordance with claim 37, wherein the monomer systemcomprises p-phenoxybenzoyl chloride.
 39. A method in accordance withclaim 37, wherein the Lewis acid is aluminum trichloride.
 40. A methodin accordance with claim 37, wherein the concentration of monomers inthe reaction medium is at least about 10% by weight based on the totalweight of the reaction mixture.
 41. A method in accordance with claim37, wherein the polymerization is conducted at a temperature in therange of -30° to +25° C.
 42. A method in accordance with claim 2,wherein the monomer system comprises an acid halide of the formula

    H--(Ar--O)n--Ar--Y


43. A method in accordance with claim 42, wherein the monomer systemcomprises p-phenoxy-p-phenoxybenzoyl chloride.
 44. A method inaccordance with claim 42, wherein the Lewis acid is aluminumtrichloride.
 45. A method in accordance with claim 42, wherein thepolymerization is conducted at a temperature in the range of -30° to+25° C.